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Copper (Cu) is the most extensively used bactericide worldwide in many agricultural production systems. However, intensive application of Cu bactericide have increased the selection pressure toward Cu-tolerant pathogens, including Xanthomonas perforans, the causal agent of tomato bacterial spot. However, alternatives for Cu bactericides are limited and have many drawbacks including plant damage and inconsistent effectiveness under field conditions. Also, potential ecological risk on nontarget organisms exposed to field runoff containing Cu is high. However, due to lack of alternatives for Cu, it is still widely used in tomato and other crops around the world in both conventional and organic production systems. In this study, a Cu-tolerant X. perforans strain GEV485, which can tolerate eight tested commercial Cu bactericides, was used in all the field trials to evaluate the efficacy of MgO nanomaterial. Four field experiments were conducted to evaluate the impact of intensive application of MgO nanomaterial on tomato bacterial spot disease severity, and one field experiment was conducted to study the impact of soil accumulation of total and bioavailable Cu, Mg, Mn, and Zn. In the first two field experiments, twice-weekly applications of 200 μg/mL MgO significantly reduced disease severity by 29-38% less in comparison to a conventional Cu bactericide Kocide 3000 and 19-30% less in comparison to the water control applied at the same frequency (p = 0.05). The disease severity on MgO twice-weekly was 12-32% less than Kocide 3000 + Mancozeb treatment. Single weekly applications of MgO had 13-19% higher disease severity than twice weekly application of MgO. In the second set of two field trials, twice-weekly applications of MgO at 1000 μg/mL significantly reduced disease severity by 32-40% in comparison to water control applied at the same frequency (p = 0.05). There was no negative yield impact in any of the trials. The third field experiment demonstrated that application of MgO did not result in significant accumulation of total and bioavailable Mg, Mn, Cu, or Zn in the root-associated soil and in soil farther away from the production bed compared to the water control. However, Cu bactericide contributed to significantly higher Mn, Cu, and Zn accumulation in the soil compared to water control (p = 0.05). This study demonstrates that MgO nanomaterial could be an alternative for Cu bactericide and have potential in reducing risks associated with development of tolerant strains and for reducing Cu load in the environment.

For the production of wood composite materials, adhesives based on cheap and affordable, but harmful urea-formaldehyde resins are mainly used. Given the substantial production volumes of such materials, it is important to find environmental solutions to reduce formaldehyde emissions during their pressing and subsequent operation. The purpose of the study was to present the results of a study on the use of magnesium oxide nanoparticles to bind unreacted formaldehyde in wood composite materials. Analysis of methods for manufacturing metal nanoparticles allowed determining a priority method that allows obtaining ultrafine structures with a size not exceeding 100 nm, namely, the method of volumetric electric spark dispersion of metals in a liquid. Investigating the morphology of magnesium nanoparticles allowed determining that they have an almost crystalline form formed from the vapour phase, with an average particle length not exceeding 100 nm. The results of spectral analysis of the element composition in the nanophase, specifically magnesium and oxygen, demonstrated that the magnesium content does not exceed 32.2%, while oxygen constitutes 67.78%. This indicates that divalent magnesium oxide does not have a pronounced metallic phase, which would interfere with the sorption processes of formaldehyde. The conducted examinations of formaldehyde emission of samples of particle boards with modified magnesium oxide nanoparticles in concentrations of 2% and 8% glue based on urea-formaldehyde resin showed mixed results. Compared to the control samples, the formaldehyde level remained almost unchanged on the second day of follow-up, and for a concentration of 2%, it even increased by 6%. However, by the sixteenth and ninetieth day, a reduction in the level of free formaldehyde emissions was observed at 19% and 22% respectively. The results obtained can be used to improve the production of non-harmful particle boards with improved properties

Abstract Due to their encouraging results, nanolubricants have been revolutionary in the field of lubrication. The degree, to which the new material may improve the tribology, energy savings, and durability, is a crucial consideration for any new additive to a conventional lubricant. The results of the earlier research on carbon, metal, metal oxide, and their composites and hybrid nanolubricants as well as their effects on tribology, are summarized in this review paper. The most popular measuring methodologies, the tribology results for lubricants with an oil base, biodegradable base, and a water base, as well as the reasons that explain these tribological advancements, are all included in this study. Finally, prospects for more study in this area are emphasized.

Polyaniline (PANI)-Fe2O3/CuO and PANI -Fe2O3/ZnO hybrid materials were developed and prepared by in situ polymerization at 0°C using ammonium persulfate as oxidant. The resulting products are investigated for their structural properties by X-ray diffraction (XRD), Fourier transform infrared (FTIR), and scanning electron microscopy (SEM), and the results confirm the formation of the hybrid architecture. In addition, the electrochemical properties of the hybrid products are investigated by cyclic voltammetry (CV) and optical properties were determined using UV-Vis Diffuse Reflectance Spectrophotometer (UV-Vis DRS). Compared to PANI/ZnO or CuO, Fe2O3/CuO or ZnO exhibit significantly improved properties. Based on the obtained results, the products thus open the way for a variety of electrical and sensors applications.

Highlights A facile and generalized design strategy of polymer precursor inks was developed for direct ink writing of metal oxide into submicron 3D architectures. The Maillard reaction between polyethyleneimine and glucose endows the 3D-printed precursors with the excellent shape fidelity during high-temperature pyrolysis. As-printed 3D periodic dielectric structure with woodpile geometry shows a significant light-matter effect in mid-infrared region.

Abstract Clean water and renewable energy sources are becoming increasingly important in the current era, as well as a future challenge, and one of the potential solutions is photocatalysis. In the current study, a simple one‐step hydrothermal technique is employed to fabricate the pure and La‐doped CuO (0%, 1%, 3%, 5%, and 7%) photocatalysts. The influence of varying La concentration on structure, morphology, and optical properties is determined by scanning electron microscope (SEM), X‐ray diffraction (XRD), ultraviolet (UV)–visible spectroscopy, and photoluminescence. SEM showed that synthesized nanostructures are irregularly spherical and transform into needle‐like nanostructures on increasing La concentration. XRD revealed the monoclinic phase with a crystallite size of 15–23 nm. The UV–visible spectrum exhibited a decrease in the band gap of La‐doped CuO needle‐like nanostructures from UV to visible light. The composition and purity of synthesized nanostructures are evaluated via the energy‐dispersive X‐ray spectrum which revealed that needle‐like nanostructures are pure without any impurity traces. The synthesized nanostructures were used as a photocatalyst against methylene blue dye to examine their photocatalytic activity. The synthesized CuO‐3La photocatalyst exhibited excellent photocatalytic performance of dye degradation and hydrogen production 95.3 μmol h−1 g−1 with more than 97% cyclic stability. Therefore, the synthesized La‐doped CuO nanostructures are potential candidates for photocatalytic water splitting and hydrogen evolution.

Although zeolitic imidazolate frameworks (ZIFs) have bright prospects in wide fields like gas storage/separation, catalysis and medicine, etc., their large-scale applications are bottlenecked by the absence of their low-cost commercial production technique. Here, we report an unconventional method suitable for environmentally friendly and low-cost mass-production of ZIFs. In this method, taking the synthesis of ZIF-8 as an example, ZnO was used instead of Zn(NO3)2 in traditional solvent synthesis methods and CO2 was introduced to dissolve ZnO in aqueous solution of 2-methylimidazole (HMeim) and form water soluble salt ([ZnMeim]+[MeimCOO]-) at room temperature. Then, by removing CO2 through heating or vacuuming, Meim-ions are produced and instantaneously assemble with [ZnMeim]+s to generate ZIF-8 without any by-product. Due to the absence of strong acid anions (such as NO3− and Cl− et al.) in solution, the washing of filter cake required in the conventional approaches could be omitted and the filtrate containing only water and HMeim could be reused completely. This method is really green as no waste gas or liquid generates because CO2 and water could be recycled perfectly. It overcomes almost all bottlenecks occurred in commercial production of ZIF-8 when using traditional methods. A pilot plant was established for mass-production of ZIF-8 and hundreds kilograms of ZIF-8 was produced, which indicates that the new method is not only environmentally friendly but also low cost and commercial accessibility. It is expected that the new method would open an avenue for commercial applications of ZIFs.

Lignin is a renewable carbon resource to produce arenes due to its abundant aromatic structures. For the liquid-phase hydrodeoxygenation (HDO) based on metallic catalysts, the preservation of aromatic rings in lignin or its derivatives remains a challenge. Herein, we synthesized Mn-doped Cu/Al2O3 catalysts from layered double hydroxides (LDHs) for liquid-phase HDO of lignin-derived anisole. Mn doping significantly enhanced the selective deoxygenation of anisole to arenes and inhibited the saturated hydrogenation on Cu/Al2O3. With Mn doping increasing, the surface of Cu particles was modified with MnOx along with enhanced generation of oxygen vacancies (Ov). The evolution of active sites structure led to a controllable adsorption geometry of anisole, which was beneficial for increasing arenes selectivity. As a result, the arenes selectivity obtained on 4Cu/8Mn4AlOx was increased to be more than 6 folds of that value on 4Cu/4Al2O3 over the synergistic sites between metal Cu and Ov generated on MnOx.

This study presents a quasi-online method for monitoring of dissolved volatile fatty acids (VFAs) in biogas fermentation processes with a carrier gas probe by use of thermo-cyclically operated metal oxide gas sensor arrays. Each of the two sensor arrays comprises a pure SnO2 and three different SnO2/additive-composites (additives: alumina, YSZ, NASICON) but differ by SnO2 synthesis routes, namely Flame Spray Pyrolysis (FSP) and Sol-Gel (SG) technique, respectively. This allowed comparative studies of the influence of layer morphology on VFA sensing characteristics. For sensitive determination of the dissolved VFAs besides high concentrations of biogas components like CO or CH4, first a pre-treatment routine of the fermentation sample was introduced to remove those physically dissolved gases without losing VFAs. The Conductance-over-Time-Profiles (CTPs) of eight different sensing layers were measured simultaneously at exposure to the gases extracted from the fermentation sample at different pH conditions. Almost all the investigated SnO2/additive-composites show CTP-features clearly correlating with the undissociated VFA even at concentrations below 120 ppm as referenced by GC-analysis. The lower detection limit is well below inhibitory concentration for fermentation processes. As expected, most pronounced CTPs representing actual VFAs situation were measured at pH 3, well below the pKa of the VFAs. The FSP-layers highlighted clearly better sensitivity and CTP specificity of higher quality compared to SG-layers. Among the SnO2/additives, the CTP-features of the SnO2(FSP)/NASICON and SnO2(SG)/NASICON layers showed the best specificity to acetic and propionic acid. For the first time, quasi-online analysis of VFAs using metal oxide gas sensors for early warning of VFA-development in biogas fermentation processes was demonstrated.

To produce the free-standing electrodes, a binder-free direct growth method was employed for electrode fabrication. A NiCo2O4@Ni-MOF (metal–organic framework) composite was synthesized using a one-pot hydrothermal method. Initially, a NiCo2O4 nanowire array was cultivated on Ni foam, serving as a connecting bridge to ensure robust adherence of the Ni-MOF to the substrate. The structures of NiCo2O4 nanowire arrays exhibit the capacity for numerous redox reactions. Hybridizing MOF with transition metal oxide (TMO) nanoarchitectures can significantly alleviate the small specific surface area and aggregation tendency of TMOs. The highest energy storage capacity was obtained when the ratio of nickel to terephthalic acid (TPA) was 4:1. NiCo2O4@Ni-MOF (Ni:[Formula: see text]:1) exhibited a high storage capacitance of 1700[Formula: see text]F/g. The integration of MOF with TMO nanoarchitectonics as materials for supercapacitor electrodes can enhance porous structure and facilitate diffusion during both charging and discharging processes.

A typical study has been performed for synthesizing Ag2O and ZnO nanoparticles. In our case, aloe vera extract was used as a reducing agent for synthesizing Ag2O. This green synthesis of silver oxide used silver nitrate (AgNO3) as a precursor material. On the other hand, the direct precipitation method was used for synthesizing zinc oxide nanoparticles, in which the precursor materials used were zinc nitrate hexahydrate (Zn(NO3)2·6H2O) and potassium hydroxide (KOH). Afterward, the characterization of these synthesized nanoparticles was done by the X-ray diffraction (XRD) method. Then, the crystal size, lattice strain, stress, and energy density of synthesized ZnO and Ag2O were determined by using XRD peak profile analysis. Among the various available models for determining these microstructural parameters, we explored the Scherrer model, the linear straight-line method of the Scherrer equation, the Monshi-Scherrer model, the Sahadat-Scherrer model, the Williamson-Hall model (including the uniform deformation model, the uniform stress deformation model, the uniform deformation energy density model), the size-strain plot method, the Halder-Wagner model, etc. By employing the crystal size values from these models, the accuracy and validity of crystals were also performed. The synthesized products were also characterized by the exploration of functional groups (by FTIR) and optical band gaps (by UV technique).

Epoxy resins have been the subject of many studies as a consequence of their extensive usage in recent years. The brittleness and low resistance to propagation and crack initiation of epoxy resins are well-recognized characteristics. Therefore, in recent years, experts have concentrated on increasing epoxy resin's fracture resistance. Adding inorganic nanoparticles like titanium dioxide (TiO2) TiO2, silica (SiO2), carbon black, alumina (Al2O3), and others to the polymer matrix is one of the most investigated techniques in polymer science. Despite having a modest nanofiller content, the resulting nanocomposites may enhance their thermal, mechanical, rheological, electrical, and optical characteristics. These nanocomposites are an alternative to metal-based materials. They have great promise as multifunctional materials in a range of applications, including optoelectronic devices, semiconductor devices, civil engineering, automotive, and aerospace. To show potential future directions and market prospects for polymer nanocomposites reinforced with TiO2 nanoparticles, current results, and trends have been examined and highlighted. In addition, the current review surveys many studies that highlighted using nanoparticles as reinforcement, their different structure, the interface, and the geometry and structure of the resulting nano-materials reinforced resin.

AbstractNanoparticles (NPs) find widespread applications in detectors, catalysis, optoelectronics, and medical devices, owing to their high surface-to-volume ratio and zero-dimensional confinement. However, addressing environmental concerns is crucial during the creation of novel nanostructured materials. Herein, ZnO NPs of different sizes were prepared via the pulsed laser ablation in liquid (PLAL) method at energies of 70, 90, and 130 mJ. The morphology and structural properties of the synthesized NPs were characterized by scanning electron microscopy, energy-dispersive X-ray spectrometry, and transmission electron microscopy. zeta-sizer and zeta-potential were used to ensure the physical stability of NPs. UV-Vis spectrophotometry measurement showed a blue shift in the band gaps with an increase in the pulsed laser energy leading to a decrease in the size of the NPs. Fourier-transform infrared spectroscopy technique confirmed the formation of ZnO NPs.

In this study, we fabricated a divergent strategy to enhance the electrochemical capacitive properties of electrodes via the cost-effective multistep green and facile electrodeposition and brush coating technique of PEDOT-TiO2/GO/PEDOT-TiO2 composite. The synthesised composite showed both EDLCs and pseudocapacitive behaviour with a good specific capacitance of 501 Fg−1 for sandwiched structure at 1 Ag−1. From the results, synthesized composite has a better ion transportation mechanism which leads to a fast charge–discharge cycle as well as a very high value of power density (500 kW/ kg) suitable for supercapacitor applications. The substance demonstrated excellent electrochemical stability, retaining 94 % of capacitance after 2000 cycles. The obtained nanocomposites were examined by FTIR, XRD, Raman, SEM-EDX and electrochemical analyses such as CV, GCD and EIS analyses. We consider that the highly stable PEDOT-TiO2/GO/PEDOT-TiO2 nanocomposite with super-capacitive behaviours is a very promising material for high-performance electrochemical storage.

The aim of this article is to provide an overview of the potential advantages and drawbacks of nanocellulose and metal oxide-based composites in food packaging. These materials offer improved mechanical and barrier properties, as well as antioxidant and antimicrobial benefits that extend the shelf life of food products. Nanocomposite structures protect food from various physiological factors and immobilize enzymes, while metal oxide nanoparticles provide antibacterial effects against Gram-positive and Gram-negative bacteria. However, there are concerns regarding the safety of nanoparticles and their potential migration into packaged food during processing and storage. This article explores these issues and highlights the need for further research to ensure the safe and effective use of these materials in food packaging. The successful implementation and commercialization of nanocellulose and metal oxide-based composites in food packaging could offer significant benefits to the food and beverage industry by improving the quality and shelf life of products.

LiCoO2 (LCO) powders were protonated and their catalytic activity on the thermal decomposition of ammonium perchlorate (AP) was tested using differential scanning calorimetry and thermogravimetric analysis. Powders were characterized using SEM, XRD, and BET surface area analysis to quantify the morphology and structure. The thermal analysis showed that protonated powders enhanced the catalytic activity in AP decomposition over commercial and unmodified LiCoO2, Fe2O3 and Co3O4 catalyst powders. The activation energies were investigated using the model-free Kissinger method, and the possible mechanisms governing the catalytic activity are discussed. The activation energies of AP thermal decomposition were decreased significantly by the use of these protonated catalysts. For neat AP, commercial LCO, and protonated LCO the activation energy for LTD and HTD were: 104 ± 5 kJ/mol and 143 ± 4 kJ/mol, 89 ± 4 kJ/mol and 92 ± 14 kJ/mol, and 76 ± 6 kJ/mol and 98 ± 7 kJ/mol respectively. We believe the hydrogen and vacancies in the protonated lattice act as reaction sites for the decomposition of AP. [ABSTRACT FROM AUTHOR]

The Tauc plot is a method originally developed to derive the optical gap of amorphous semiconductors such as amorphous germanium or silicon. By measuring the absorption coefficient α(hν) and plotting (αhv)12$(\alpha {hv})^{\frac{1}{2}}$ versus photon energy hν, a value for the optical gap (Tauc gap) is determined. In this way non‐direct optical transitions between approximately parabolic bands can be examined. In the last decades, a modification of this method for (poly‐) crystalline semiconductors has become popular to study direct and indirect interband transitions. For this purpose, (ahν)n (n = 12$\frac{1}{2}$, 2) is plotted against hν to determine a value of the electronic bandgap. Due to the ease of performing UV–vis measurements, this method has nowadays become a standard to analyze various (poly‐) crystalline solids, regardless of their different electronic structure. Although this leads partially to widely varying values of the respective bandgap of nominally identical materials, there is still no study that critically questions which peculiarities in the electronic structure prevent a use of the Tauc plot for (poly‐) crystalline solids and to which material classes this applies. This study aims to close this gap by discussing the Tauc plot and its limiting factors for exemplary (poly‐) crystalline solids with different electronic structures. [ABSTRACT FROM AUTHOR]

With the increasing attention to health, especially the impact of COVID-19 in recent years, the research and application of antimicrobial materials have gradually become a research hotspot. Adding antimicrobial agents to various materials is the most common, simple, and effective processing method. The activity of antimicrobial agent has a great influence on the effect and use of antimicrobial material. The photocatalytic metal oxides have the advantages of high antimicrobial performance and long-term activity. In this paper, the antimicrobial mechanisms, types, and applications of photocatalytic metal oxides were described, focusing on the research status and existing problems of photocatalytic metal oxides and doped metal oxides commonly used as inorganic antimicrobials. The future application prospect and research directions of photocatalytic metal oxide antimicrobials were proposed. [ABSTRACT FROM AUTHOR]

In this study, hybrid polymer nanocomposites were produced by combining epoxy (EP) with varying amounts of zirconia (ZrO 2) and yttria (Y2O 3) nanoparticles (NPs), reinforced with multi-walled carbon nanotube (MWCNT) and glass fiber (GF). The objective of this study is to develop and examine the performance of EP nanocomposites through hybridization; for this purpose, hardness and impact tests were conducted in accordance with American Society for Testing and Materials (ASTM) standards. Different sets were produced to investigate the effect of used fillers, including EP/ZrO2, EP/Y2O3, EP/MWCNT, EP/GF, EP/ZrO2/Y2O3, EP/MWCNT/ZrO2/Y2O3, and EP/MWCNT/GF/ZrO2/Y2O3. All findings were compared with the net EP sample. The results showed that the EP nanocomposite samples with low NPs content exhibit much higher mechanical performance than net EP. Furthermore, the additions of MWCNT and GF separately at 0.1 and 0.06 wt.% have increased the impact strength, respectively, to 165.2% and 338.8%, compared with pure EP. As a result, the presence of MWCNTs and GF in the EP-based nanocomposite matrix could make the product both stronger and tougher. [ABSTRACT FROM AUTHOR]

In this research, a nano-inorganic composite of CuO/NiO is prepared by co-precipitation method as an efficient recyclable nanocatalyst for the regioselective synthesis of 1,4-disubstituted-1,2,3-triazoles in water. The catalyst was characterized by several techniques such as the field emission scanning electron microscopy (FESEM), energy dispersive spectroscopy (EDS), x-ray diffraction (XRD), transmission electron microscopy (TEM), thermogravimetric analysis (TGA), x-ray fluorescence, inductively coupled plasma atomic emission spectroscopy (ICP-OES), and brunauer-emmett-teller (BET) surface area analysis. The regioselective synthesis of 1,4-disubstituted-1,2,3-triazoles was carried out from reaction of various benzyl halides or alkyl halides with phenyl acetylene and sodium azide in water under reflux condition in high yields. The CuO/NiO nanocatalyst can be simply recovered and reused 6 runs without a significant slight in activity. [ABSTRACT FROM AUTHOR]

Cement-based materials with thermoelectric effect can realize the conversion of waste heat in building environment, which is of great significance in energy conversion and utilization, and has become a research hotspot in recent years. In this study, three kinds of metal oxides were added into the phase change modified expanded graphite cement-based composites to investigate the impact of metal oxide content on the thermoelectric characteristics of cement composites. The findings shown that the thermoelectric properties of cement-based materials can be enhanced by the addition of metal oxides. The power factor increased to 3.15 μW·m−1·K−2, 3.60 μW·m−1·K−2, and 2.53 μW·m−1·K−2 after mixing ZnO, CuO, and TiO2. This is because the incorporation of metal oxides introduced a large number of interfaces into the cement, increased carrier scattering, strengthened the Seebeck coefficient of cement, and improved the power factor. This work presented a novel strategy to improving the thermoelectric properties of cement-based materials. [ABSTRACT FROM AUTHOR]

Sodium-modified litho-vanadium glasses containing non-magnetic Aluminium ions of composition 50Li2CO3 - (30-X) Na2 CO3-20V2O5 -xAl2O3 (30 = x = 5) (LNVA) glasses were prepared by melt quenching technique. The density of the glass samples was measured and found to increase with the Aluminium content of the glass matrix. The measured values of refractive index and polaron radius of the glass network show opposite behaviour with an increase of Aluminium content. Through band gap energy and refractive index, Oxide ion polarizability and electronic polarizability were determined by using the Lorentz-Lorenz equation. The value of Oxide ion polarizability and electronic polarizability is found to be decreased with decreasing band gap energy and increasing refractive index. The value of optical basicity was measured using electronic polarizability and is found to be decreased with decreasing inter-nuclear distance. The band gap energy values of the glass network were found to decrease from 3.241 to 2.134 eV. The metallisation criterion of the glass material was calculated and found to decrease with Aluminium content. [ABSTRACT FROM AUTHOR]

We synthesized zinc oxide nanoparticles (ZnO NPs) by meticulously controlling both temperature and reaction times, allowing us to fine-tune their crystalline properties, morphology, and particle dimensions. This analysis confirmed the existence of a mixture of rod and sphere shapes (ZnO-I), including rod-shaped NPs with an average size of 14.8 nm × 5.2 nm and spherical NPs with an average diameter of 5.27 nm. We subsequently incorporated these synthesized ZnO NPs into organic light-emitting diode (OLED) devices for red, green, and blue colors, utilizing them as the electron injection layer through a solution-based process. The green OLED device using ZnO-I exhibited a promising current efficiency of 4.02 cd/A and an external quantum efficiency of 1.47%. [ABSTRACT FROM AUTHOR]

Separation of thorium, uranium, and rare earth elements (REEs) requires selective materials with high capacity, good thermal, chemical and radiation resistance. For this aim, Zr, Si and Ti oxide nanoparticles (NPs) have been prepared using metal alkoxide precursors via hydrothermal method. Polyacrylonitrile (PAN) was used as a supporting material to obtain nanocomposite (NC) beads for the potential use in industrial scale applications. The surface characteristics and morphological properties of nano metal oxide powders and composites were determined. Metal uptake and separation studies of thorium and REEs were carried out from sulfuric acid leach solution of Beylikova ore. [ABSTRACT FROM AUTHOR]

Herein, the structure, thermal stability, optical, magnetic characteristics, and adsorption performance towards methylene blue (MB) of Sn 1- x Zn 2 x Cr 2 O 5 nanocomposites (x = 0, 0.2, 0.4, 0.5, 0.6, 0.8, and 1), prepared by the hydrothermal method, were investigated. The crystal structures, elemental chemical compositions and surface morphology were conducted using XRD, TEM, EDX, and SEM techniques. The structural parameters significantly depend on the elemental composition. For example, a tetragonal SnO 2 phase was formed at x = 0, and 0.2, while a spinel-structured ZnCr 2 O 4 was formed at x ≥ 0.4 beside the orthorhombic CrO 3 phases. The mass magnetic susceptibility and magnetization of the Sn 1- x Zn 2 x Cr 2 O 5 nanocomposites displayed a weak room temperature ferromagnetism behavior. The maximum surface area (100.89 m2/g), evaluated via the Brunauer-Emmett-Teller method, was achieved for Sn 0.6 Zn 0.8 Cr 2 O 5 nanocomposite. The optical band gap and Urbach energy show opposite trends and are slightly influenced by Zn content. Moreover, the impact of the Zn2+ ratio on the structure, optical, thermal stability, and magnetic characteristics was correlated. The adsorption performance of the Sn 1- x Zn 2 x Cr 2 O 5 nanocomposite (0 ≤ x ≤ 0.6) revealed an excellent removal efficiency (max ∼87.64%) towards MB dye with apparent rate kinetic constant of 44.9 × 10–2 min–1. [ABSTRACT FROM AUTHOR]

The incineration of agricultural waste (agro-waste) as a fuel or solid fuel results in landfilled ash that in most cases results in an environmental problem in its disposal. We highlighted an excellent overview for the utilization of different types of agricultural waste, such as rice husk and straw, sugarcane bagasse, bamboo leaves, banana peel, onion peel, and other agricultural waste employed for the fabrication of low-cost, environmentally friendly, and high potential range nanomaterials. In this review, we summarized the synthesis process and applications of metal oxide nanomaterials such as ZnO and SiO2, which are promising value-added material for various purposes, using agricultural waste as raw material. We have also discussed different applications, toxic effects as well as management of agricultural waste by the "3R" strategy of the agricultural waste management system. We conclude this review by suggesting future applications of agricultural waste as well as providing protective measures against global pollution. [ABSTRACT FROM AUTHOR]

Welding fumes contain harmful metals and gas by-products associated with development of lung dysfunction, asthma, bronchitis, and lung cancer. Two prominent welding fume particulate metal components are nanosized iron (Fe) and manganese (Mn) which might induce oxidative stress and inflammation resulting in pulmonary injury. Welding fume toxicity may be dependent upon metal nanoparticle (NP) components. To examine toxicity of welding fume NP components, a system was constructed for controlled and continuous NP generation from commercial welding and customized electrodes with varying proportions of Fe and Mn. Aerosols generated consisted of nanosized particles and were compositionally consistent with each electrode. Human alveolar lung A459 epithelial cells were exposed to freshly generated metal NP mixtures at a target concentration of 100 µg/m3 for 6 hr and then harvested for assessment of cytotoxicity, generation of reactive oxygen species (ROS), and alterations in the expression of genes and proteins involved in metal regulation, inflammatory responses, and oxidative stress. Aerosol exposures decreased cell viability and induced increased ROS production. Assessment of gene expression demonstrated variable up-regulation in cellular mechanisms related to metal transport and storage, inflammation, and oxidative stress based upon aerosol composition. Specifically, interleukin-8 (IL-8) demonstrated the most robust changes in both transcriptional and protein levels after exposure. Interleukin-8 has been determined to serve as a primary cytokine mediating inflammatory responses induced by welding fume exposures in alveolar epithelial cells. Overall, this study demonstrated variations in cellular responses to metal NP mixtures suggesting compositional variations in NP content within welding fumes may influence inhalation toxicity. [ABSTRACT FROM AUTHOR]

Herein, we report a simple non-enzymatic electrochemical sensor for the detection of serotonin (5-HT) in blood serum using ZnO oxide nanoparticles-copper metal-organic framework (MOF) composite on 3D porous nickel foam, namely, ZnO-Cu MOF/NF. The x-ray diffraction analysis reveals the crystalline nature of synthesized Cu MOF and Wurtzite structure of ZnO nanoparticles, whereas SEM characterization confirms the high surface area of the composite nanostructures. Differential pulse voltammetry analysis under optimal conditions yields a wide linear detection range of 1 ng ml−1 to 1 mg ml−1 to 5-HT concentrations and a LOD (signal to noise ratio = 3.3) of 0.49 ng ml−1, which is well below the lowest physiological concentration of 5-HT. The sensitivity of the fabricated sensor is found to be 0.0606 mA ng−1 ml−1.cm2, and it exhibited remarkable selectivity towards serotonin in the presence of various interferants, including dopamine and AA, which coexist in the real biological matrix. Further, successful determination of 5-HT is achieved in the simulated blood serum sample with a good recovery percentage from ∼102.5% to ∼99.25%. The synergistic combination of the excellent electrocatalytic properties and surface area of the constituent nanomaterials proves the overall efficacy of this novel platform and shows immense potential to be used in developing versatile electrochemical sensors. [ABSTRACT FROM AUTHOR]

In the last several decades, metal oxide thin films have attracted significant attention for the development of various existing and emerging technological applications, including pH sensors. The mandate for consistent and precise pH sensing techniques has been increasing across various fields, including environmental monitoring, biotechnology, food and agricultural industries, and medical diagnostics. Metal oxide thin films grown using physical vapor deposition (PVD) with precise control over film thickness, composition, and morphology are beneficial for pH sensing applications such as enhancing pH sensitivity and stability, quicker response, repeatability, and compatibility with miniaturization. Various PVD techniques, including sputtering, evaporation, and ion beam deposition, used to fabricate thin films for tailoring materials' properties for the advanced design and development of high-performing pH sensors, have been explored worldwide by many research groups. In addition, various thin film materials have also been investigated, including metal oxides, nitrides, and nanostructured films, to make very robust pH sensing electrodes with higher pH sensing performance. The development of novel materials and structures has enabled higher sensitivity, improved selectivity, and enhanced durability in harsh pH environments. The last decade has witnessed significant advancements in PVD thin films for pH sensing applications. The combination of precise film deposition techniques, novel materials, and surface functionalization strategies has led to improved pH sensing performance, making PVD thin films a promising choice for future pH sensing technologies. [ABSTRACT FROM AUTHOR]

The ternary composite MgO@ZnO@BC was synthesized and characterized for the adsorption of Cu2+, Pb2+ heavy metal ions from wastewater. The results show that the addition of the MgO@ZnO@BC composite results in higher adsorption properties for Cu2+ and Pb2+, with a molar ratio of 5% 0.1 g, and maximum adsorption capacity (50.63 mg/g for Cu2+ and 61.46 mg/g for Pb2+). The Langmuir adsorption isotherm of the adsorption complex and the kinetics of adsorption are secondary kinetics. The adsorption of Cu2+ and Pb2+ was mainly chemisorption, accompanied by physical adsorption. This adsorption method fully conforms to the concepts of clean production and efficient waste utilization, providing a reference for the removal of heavy metal ions from wastewater and waste recycling using ternary composite materials. [ABSTRACT FROM AUTHOR]

Electrochemical reduction processes of oxides in molten salt have been proposed as the carbon-free technologies in order to achieve carbon neutrality. The anodic behavior of La1−xSrxFeO3−δ as an O2 evolution anode in LiCl–KCl at 723 K was investigated. The results suggested that at 723 K, the electrical conductivity of La1−xSrxFeO3−δ tended to increase with the Sr doping. The anodic reactions of the La1−xSrxFeO3−δ electrodes were characterized by electrochemical measurements in LiCl–KCl + Li2O at 723 K. Based on the cyclic voltammograms of the La0.7Sr0.3FeO3−δ electrode, O2 evolution has proceeded between 2.7 and 3.6 V. The potential of the La0.7Sr0.3FeO3−δ electrode during galvanostatic electrolysis has conducted at 39 mA cm−2 for 15 h has remained stable at 2.8 V, indicating that the stable evolution of O2 gas was monitored. The corrosion rate was estimated to have the low value of 8.6 × 10−4 g cm−2 h−1. Electrode surface data obtained after electrolysis indicated that the La0.7Sr0.3FeO3−δ electrode exhibited excellent chemical and physical stability in LiCl–KCl at 723 K. This indicates that the La0.7Sr0.3FeO3−δ electrode is promising candidate material as inert anodes for oxide decomposition. As an application of the La0.7Sr0.3FeO3−δ electrode, the electrolytic reduction of CO2 was also successfully achieved. [ABSTRACT FROM AUTHOR]

A sulfur treatment based on the supercritical fluid (SCF) treatment is proposed and its effect on the silver (Ag)‐doped material and device is investigated. The sulfur treatment is achieved by mixing sulfur powder with carbon dioxide (CO2) in a reaction chamber under high pressure (3000 psi) at low reacting temperature (120 °C). Based on the experimental results, the SCF sulfur treatment can dramatically change the Ag‐doped SiO2 (Ag:SiO2) thin‐film characteristics, including surface morphology, crystallization, chemical bonding, and mole elements in accordance with the analyses of various materials. In addition, the SCF sulfur treatment is also applied to the Ag:SiO2‐based device to verify the resistance switching (RS) properties. Based on electrical measurement results, the device with the SCF sulfur treatment exhibits better performance. The graduate RS behaviors also exhibit multilevel switching in both set and reset processes, which proves its possible applications of the proposed SCF sulfur treatment. In addition, the current fitting method is used to verify the RS properties to illustrate the carrier transportation characteristics of the Ag:SiO2‐based device with the SCF sulfur treatment. [ABSTRACT FROM AUTHOR]

Various studies have been made to obtain high efficiency photocatalysts. Auvirillius bismuth titanate oxide is known to have good photocatalytic activity to degrade dyestuffs. However, recombination is still an obstacle to photocatalytic efficiency. To overcome recombination and increase photocatalytic activity, it is proposed to synthesize bismuth titanate heterophase. Heterophase can enhance the formation of the synergistic effect of electrons, which effectively stimulates the transfer of electrons from 1 phase to another. This study aims to determine the photocatalytic ability of bismuth titanate heterophase for degradation of a rhodamine B. Bismuth titanate was synthesized by hydrothermal method using Bi2O3 and TiO2 precursors. The results of X-ray diffraction characterization showed that the synthesized bismuth titanate formed 2 phases, namely Bi4Ti3O12 (78.2 %) and Bi12Ti0.9O19.8 (21.8 %). In addition, it is also known that the volume of the synthesized bismuth titanate crystal lattice has a smaller volume than the standard synthesized in previous studies. The photocatalytic ability of bismuth titanate evaluated using 10 mg/L rhodamine B showed that it took 240 min to degrade 98 % of dye. Reaction kinetics studies showed that bismuth titanate has a reaction rate constant efficiency of 120 % better than TiO2 for the Langmuir-Hinshelwood 1st-order kinetic model. Then the reuse ability was evaluated, showing that after 3 times of uses, bismuth titanate only decreased 5 %, whereas TiO2 decreased by 7 % in degradation. [ABSTRACT FROM AUTHOR]

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Nowadays, indoor air pollution is a major problem that affects human health. For that reason, measuring indoor air quality has an increasing interest. Electronic noses are low-cost instruments (compared with reference methods) capable of measuring air components and pollutants at different concentrations. In this paper, an electro-optical nose (electronic nose that includes optical sensors) with non-dispersive infrared sensors and metal oxide semiconductor sensors is used to measure gases that affect indoor air quality. To validate the developed prototype, different gas mixtures (CH4 and CO2) with variable concentrations and humidity values are generated to confirm the discrimination capabilities of the device. Principal Component Analysis (PCA) was used for dimensionality reduction purposes to show the measurements in a plot. Partial Least Squares Regression (PLS) was also performed to calculate the predictive capabilities of the device. PCA results using all the measurements from all the sensors obtained PC1 = 47% and PC2 = 10%; results are improved using only the relevant information of the sensors obtaining PC1 = 79% and PC2 = 9%. PLS results with CH4 using only MOX sensors received an RMSE = 118.8. When using NDIR and MOX sensors, RMSE is reduced to 19.868; this tendency is also observed in CO2 (RMSE = 116.35 with MOX and RMSE = 20.548 with MOX and NDIR). The results confirm that the designed electro-optical nose can detect different gas concentrations and discriminate between different mixtures of gases; also, a better correlation and dispersion is achieved. The addition of NDIR sensors gives better results in measuring specific gases, discrimination, and concentration prediction capabilities in comparison to electronic noses with metal oxide gas sensors. [ABSTRACT FROM AUTHOR]

By supporting platinum (Pt) and cadmium sulfide (CdS) nanoparticles on indium oxide (In2O3), we fabricated a CdS/Pt/In2O3 photocatalyst. Selective photoreduction of carbon dioxide (CO2) to methane (CH4) was achieved on CdS/Pt/In2O3 with electronic Pt−In2O3 interactions, with CH4 selectivity reaching to 100 %, which is higher than that on CdS/Pt/In2O3 without electronic Pt−In2O3 interactions (71.7 %). Moreover, the enhancement effect of electronic Pt‐(metal‐oxide) interactions on selective photoreduction of CO2 to CH4 also occurs by using other common metal oxides, such as photocatalyst supports, including titanium oxide, gallium oxide, zinc oxide, and tungsten oxide. The electronic Pt‐(metal‐oxide) interactions separate photogenerated electron‐hole pairs and convert CO2 into CO2δ−, which can be easily hydrogenated into CH4 via a CO2δ−→HCOO*→HCO*→CH*→CH4 path, thus boosting selective photoreduction of CO2 to CH4. This offers a new way to achieve selective photoreduction of CO2. [ABSTRACT FROM AUTHOR]

By supporting platinum (Pt) and cadmium sulfide (CdS) nanoparticles on indium oxide (In2O3), we fabricated a CdS/Pt/In2O3 photocatalyst. Selective photoreduction of carbon dioxide (CO2) to methane (CH4) was achieved on CdS/Pt/In2O3 with electronic Pt−In2O3 interactions, with CH4 selectivity reaching to 100 %, which is higher than that on CdS/Pt/In2O3 without electronic Pt−In2O3 interactions (71.7 %). Moreover, the enhancement effect of electronic Pt‐(metal‐oxide) interactions on selective photoreduction of CO2 to CH4 also occurs by using other common metal oxides, such as photocatalyst supports, including titanium oxide, gallium oxide, zinc oxide, and tungsten oxide. The electronic Pt‐(metal‐oxide) interactions separate photogenerated electron‐hole pairs and convert CO2 into CO2δ−, which can be easily hydrogenated into CH4 via a CO2δ−→HCOO*→HCO*→CH*→CH4 path, thus boosting selective photoreduction of CO2 to CH4. This offers a new way to achieve selective photoreduction of CO2. [ABSTRACT FROM AUTHOR]

By supporting platinum (Pt) and cadmium sulfide (CdS) nanoparticles on indium oxide (In2O3), we fabricated a CdS/Pt/In2O3 photocatalyst. Selective photoreduction of carbon dioxide (CO2) to methane (CH4) was achieved on CdS/Pt/In2O3 with electronic Pt−In2O3 interactions, with CH4 selectivity reaching to 100 %, which is higher than that on CdS/Pt/In2O3 without electronic Pt−In2O3 interactions (71.7 %). Moreover, the enhancement effect of electronic Pt‐(metal‐oxide) interactions on selective photoreduction of CO2 to CH4 also occurs by using other common metal oxides, such as photocatalyst supports, including titanium oxide, gallium oxide, zinc oxide, and tungsten oxide. The electronic Pt‐(metal‐oxide) interactions separate photogenerated electron‐hole pairs and convert CO2 into CO2δ−, which can be easily hydrogenated into CH4 via a CO2δ−→HCOO*→HCO*→CH*→CH4 path, thus boosting selective photoreduction of CO2 to CH4. This offers a new way to achieve selective photoreduction of CO2. [ABSTRACT FROM AUTHOR]

By supporting platinum (Pt) and cadmium sulfide (CdS) nanoparticles on indium oxide (In2O3), we fabricated a CdS/Pt/In2O3 photocatalyst. Selective photoreduction of carbon dioxide (CO2) to methane (CH4) was achieved on CdS/Pt/In2O3 with electronic Pt−In2O3 interactions, with CH4 selectivity reaching to 100 %, which is higher than that on CdS/Pt/In2O3 without electronic Pt−In2O3 interactions (71.7 %). Moreover, the enhancement effect of electronic Pt‐(metal‐oxide) interactions on selective photoreduction of CO2 to CH4 also occurs by using other common metal oxides, such as photocatalyst supports, including titanium oxide, gallium oxide, zinc oxide, and tungsten oxide. The electronic Pt‐(metal‐oxide) interactions separate photogenerated electron‐hole pairs and convert CO2 into CO2δ−, which can be easily hydrogenated into CH4 via a CO2δ−→HCOO*→HCO*→CH*→CH4 path, thus boosting selective photoreduction of CO2 to CH4. This offers a new way to achieve selective photoreduction of CO2. [ABSTRACT FROM AUTHOR]

Metal oxide nanowires (NWs) with a high surface area, ease of fabrication, and precise control over diameter and chemical composition are among the best candidates for the realization of resistive gas sensors. Among the different techniques used for the synthesis of materials with NW morphology, approaches based on the vapor–liquid–solid (VLS) mechanism are very popular due to the ease of synthesis, low price of starting materials, and possibility of branching. In this review article, we discuss the gas-sensing features of metal oxide NWs grown by the VLS mechanism, with emphasis on the growth conditions and sensing mechanism. The growth and sensing performance of SnO2, ZnO, In2O3, NiO, CuO, and WO3 materials with NW morphology are discussed. The effects of the catalyst type, growth temperature, and other variables on the morphology and gas-sensing performance of NWs are discussed. [ABSTRACT FROM AUTHOR]

The contamination of water by organic substances poses a significant global challenge. To address these pressing environmental and energy concerns, this study emphasizes the importance of developing effective photocatalysts powered by sunlight. In this research, we achieved the successful synthesis of a novel photocatalyst comprised of polymeric carbon nitride (CN) nanosheets embedded with Co3O4 material, denoted as CN-CO. The synthesis process involved subjecting the mixture to 500 °C for 10 h in a muffle furnace. Structural and morphological analyses confirmed the formation of CN-CO nanostructures, which exhibited remarkable enhancements in photocatalytic activity for the removal of methylene blue (MB) pollutants under replicated sunlight. After 90 min of exposure, the degradation rate reached an impressive 98.9%, surpassing the degradation rates of 62.3% for pure CN and 89.32% for pure Co3O4 during the same time period. This significant improvement can be attributed to the exceptional light captivation capabilities and efficient charge separation abilities of the CN-CO nanostructures. Furthermore, the CN-CO nanostructures demonstrated impressive photocurrent density-time (j-t) activity under sunlight, with a photocurrent density of 2.51 μA/cm2 at 0.5 V. The CN-CO nanostructure exhibited excellent methanol oxidation reaction (MOR) activity with the highest current density of 83.71 mA/cm2 at an optimal 2 M methanol concentration, benefiting from the synergy effects of CN and CO in the nanostructure. Overall, this study presents a straightforward and effective method for producing CN-based photocatalysts decorated with semiconductor nanosized materials. The outcomes of this research shed light on the design of nanostructures for energy-related applications, while also providing insights into the development of efficient photocatalytic materials for addressing environmental challenges. [ABSTRACT FROM AUTHOR]